Three US firefighters killed in southern NSW plane

Three US firefighter have been confirmed dead in an aircraft crash into the Snowy Monaro area of southern NSW.

The C-130 Hercules was being used to battle emergency-level bushfires in the region when the crash occurred late Thursday afternoon.

NSW Rural Fire Service (RFS) Commissioner Shane Fitzsimmons confirmed the tragic news in a press conference. 

"Tragically, there appears to be no survivors as a result of the crash down in the Snowy Monaro area," he said. 

"[The aircraft] impacted heavily with the ground and initial reports are that there was a large fireball associated with the impact of the plane as it hit the ground." 

The aviation company has landed their planes in a sign of respect. 

"As a precaution and a standard precaution, Coulsons have grounded their large air tankers this afternoon, and, indeed, as a mark of respect and as welfare for the rest of their crews operating large air tankers here in New South Wales and interstate in Victoria," Fitzsimmons said. 

NSW Premier Gladys Berejiklian also offered her condolences. 

"Our thoughts are not just with family and loved ones but for anyone who feels impacted by what has unfolded this afternoon," she said. 

"We can't thank enough people who continue, notwithstanding the conditions, to put their safety at risk to protect lives and property of others."